1 files changed, 141 insertions, 0 deletions
diff --git a/gr-blocks/lib/delay_impl.cc b/gr-blocks/lib/delay_impl.cc
new file mode 100644
index 000000000..67449aca2
--- /dev/null
+++ b/gr-blocks/lib/delay_impl.cc
@@ -0,0 +1,141 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007,2010,2012-2013 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "delay_impl.h"
+#include <gr_io_signature.h>
+#include <string.h>
+
+namespace gr {
+  namespace blocks {
+
+    delay::sptr
+    delay::make(size_t itemsize, int delay)
+    {
+      return gnuradio::get_initial_sptr
+        (new delay_impl(itemsize, delay));
+    }
+
+    delay_impl::delay_impl(size_t itemsize, int delay)
+      : gr_block("delay",
+                 gr_make_io_signature(1, -1, itemsize),
+                 gr_make_io_signature(1, -1, itemsize)),
+        d_itemsize(itemsize)
+    {
+      set_dly(delay);
+      d_delta = 0;
+    }
+
+    delay_impl::~delay_impl()
+    {
+    }
+
+    void
+    delay_impl::forecast(int noutput_items,
+                         gr_vector_int &ninput_items_required)
+    {
+      // make sure all inputs have noutput_items available
+      unsigned ninputs = ninput_items_required.size();
+      for(unsigned i = 0; i < ninputs; i++)
+        ninput_items_required[i] = noutput_items;
+    }
+
+    void
+    delay_impl::set_dly(int d)
+    {
+      // only set a new delta if there is a change in the delay; this
+      // protects from quickly-repeated calls to this function that
+      // would end with d_delta=0.
+      if(d != dly()) {
+        gruel::scoped_lock l(d_mutex_delay);
+        int old = dly();
+        set_history(d+1);
+        d_delta += dly() - old;
+      }
+    }
+
+    int
+    delay_impl::general_work(int noutput_items,
+                             gr_vector_int &ninput_items,
+                             gr_vector_const_void_star &input_items,
+                             gr_vector_void_star &output_items)
+    {
+      gruel::scoped_lock l(d_mutex_delay);
+      assert(input_items.size() == output_items.size());
+
+      const char *iptr;
+      char *optr;
+      int cons, ret;
+
+      // No change in delay; just memcpy ins to outs
+      if(d_delta == 0) {
+        for(size_t i = 0; i < input_items.size(); i++) {
+          iptr = (const char *)input_items[i];
+          optr = (char *)output_items[i];
+          std::memcpy(optr, iptr, noutput_items*d_itemsize);
+        }
+        cons = noutput_items;
+        ret = noutput_items;
+      }
+
+      // Skip over d_delta items on the input
+      else if(d_delta < 0) {
+        int n_to_copy, n_adj;
+        int delta = -d_delta;
+        n_to_copy = std::max(0, noutput_items-delta);
+        n_adj = std::min(delta, noutput_items);
+        for(size_t i = 0; i < input_items.size(); i++) {
+          iptr = (const char *) input_items[i];
+          optr = (char *) output_items[i];
+          std::memcpy(optr, iptr+delta*d_itemsize, n_to_copy*d_itemsize);
+        }
+        cons = noutput_items;
+        ret = n_to_copy;
+        delta -= n_adj;
+        d_delta = -delta;
+      }
+
+      //produce but not consume (inserts zeros)
+      else {  // d_delta > 0
+        int n_from_input, n_padding;
+        n_from_input = std::max(0, noutput_items-d_delta);
+        n_padding = std::min(d_delta, noutput_items);
+        for(size_t i = 0; i < input_items.size(); i++) {
+          iptr = (const char *) input_items[i];
+          optr = (char *) output_items[i];
+          std::memset(optr, 0, n_padding*d_itemsize);
+          std::memcpy(optr, iptr, n_from_input*d_itemsize);
+        }
+        cons = n_from_input;
+        ret = noutput_items;
+        d_delta -= n_padding;
+      }
+
+      consume_each(cons);
+      return ret;
+    }
+
+  } /* namespace blocks */
+} /* namespace gr */